The baby boomers, long known as master acquirers, are now learning a new skill: getting rid of excess stuff. Some are empty nesters moving to smaller digs. Others are helping their aging parents sort through their belongings before a move or are disposing of items in the wake of a parent’s death.

Call it downsizing, deaccessioning (museum lingo), or decommissioning (the military term). Regardless of what you call it and why you’re selling off personal treasures, your goal should be the same: to get as much as possible for your things, with as little emotional and physical strain as possible.

Here are ten tips to help you decide what to keep, sell, donate, or gift and when to call in professional help.

1. Accept that downsizing is tough.

Penny Catterall makes her living as a professional organizer out of Bethesda, Md. Now she is helping her own 77-year-old widowed mom, Bilha Bryant, sort through and clear out possessions built up over decades in her 5-bedroom Spanish colonial in Washington, D.C. to prepare for a move to a rental apartment in the pedestrian-friendly Friendship Heights neighborhood near Catterall.

In May, mother and daughter staged a one-day private sale at Bryant’s house of items collected during her late dad’s 33-year-career in the foreign service including embroidered textiles from India, Afghani tribal jewelry, African masks and Korean celadon vases. Total take from the sale, which Catterall promoted on her neighborhood’s Yahoo Group: $4,000.

Yet even as an organizing pro, Catterall found it tough. “I had the most massive migraine,” she said the day after the sale. “It was very personal.”